This invention relates to a sound field control device capable of producing a tone having a tonal effect (hereinafter referred to as "sound field effect tone") which provides a listener with a feeling of presence as if he was listening to the music in a different sound field such as a spacious concert hall, church or stadium notwithstanding the fact that he is actually in an ordinary room or listening room. More particularly, this invention relates to a sound field control device of this type capable of automatically establishing a sound field which is most suited to a musical scene or video scene reproduced.
For realizing a feeling of presence of a different sound field such as a concert hall in an ordinary listening room or the like place, auxiliary loudspeakers are disposed around a listener in addition to ordinary main loudspeakers and sound field tones such as reverberating tones and rear tones of source signals are sounded from these auxiliary loudspeakers.
There are prior art sound field control devices which produce sound field effect tones by utilizing sound field effect tone components contained in source signals Another type of prior art sound field control device creates new sound field effect tones without depending upon sound field effect tone components contained in source signals.
As an example of the former type of prior art sound field control device, there is a device which extracts reverberation components after subjecting signals of left and right channels to subtraction between them and subjects the extracted reverberation components to processings such as reinforcement, delay and phase-shifting to produce sound field effect tones. As another example of the former type of prior art sound field control device, there is a device called a 4-channel system which transfers tones of 4 channels, i.e., front left and right tones and rear left and right tones, in a transmission system of 2 channels by encoding these tones into tones of 2 channels by the employment of a discrete system or matrix system and thereafter decoding these tones into 4-channel tones in the playback device.
As an example of the latter type of prior art sound field control device, there is a device which creates reverberation tones artificially by applying source signals to a reverberator.
In the prior art sound field control device utilizing sound field effect tone components contained in source signals, the tonal effect obtained is limited due to limited capacity of the transmission system such as a record and tape. Besides, the tonal effect is a fixed one and the listener cannot adjust the effect as he desires.
In the prior art sound field control device which creates new sound field effect tones without depending upon sound field effect tone components contained in source signals, a greater tonal effect can be obtained since sound field effect tones can be produced irrespective of reverberation components contained in source signals and, also the listener can adjust the tonal effect in various manners. In this latter device, however, the listener must adjust parameters such as room size, liveness, reverberation time and reverberation level each time he wants to obtain a feeling of presence suitable for a reproduced music scene or video scene. This involves a somewhat troublesome adjusting operation.
It is, therefore, an object of the invention to provide a sound field control device of the type creating new sound field effect tones without depending upon sound field effect tones contained in source signals which is capable of automatically setting a sound field most suited to a reproduced musical scene or video scene.